Answer: All reals
Reason:
Absolute value represents distance on a number line. Specifically it's the distance from x to 0.
For example, |-2| = 2 means -2 is 2 units away from 0.
Since |x| represents a distance, we cannot have negative distance. So |x| is either 0 or positive. Furthermore, it means |x| is larger than any negative value you pick.
Therefore, |x| > -9 is true for any x value and it's why we go for "all reals" (aka "all real numbers")
